The present invention relates to an applicator, which can, for instance, be used for taking a sample from a blood-containing test tube to test blood. The applicator may also serve as a syringe to administer a drug to a patient, or to take blood directly from a patient. The above are only examples of possible
When the piston is retracted in a conventional applicator to suck liquid into the cylinder, the operator normally needs use of both hands, namely one for retracting the piston while the other hand is holding the cylinder. As a consequence, the operator is not capable of performing another operation or, for instance, of holding a receptacle into which the liquid sample is to be discharged from the applicator.
DE 36 09 555 A1 discloses a blood collecting syringe with a canula and a cylinder in which a piston is slidably arranged for drawing a medium into the cylinder. This blood collecting syringe is equipped with racks and gears for operation with one hand only. This is a complicated mechanism for a blood collecting syringe.
EP 166 010 A1 discloses an apparatus for drawing blood from the body, the blood being poisoned by the bite of a reptile. This apparatus comprises a spring between cylinder and piston, the spring being biased such that it acts on the piston with a force driving the same into a retracted position. Moreover, there is a component which serves to sealingly position the apparatus on the skin near the bite wound.